The invention concerns a plug-in connection for joining pipelines and hose lines.
A typical plug-in connection has become known, for example, from the disclosure of German Patent No. DE 38 13 192 A1. This typical plug-in connection basically consists of an outer plastic sleeve, which engages, by a sealing shoulder, with a corresponding receptacle on an inner sleeve. The inner sleeve has a groove opening radially outward in which a sealing ring is inserted. The disadvantage of this plug-in coupling is that the outer plastic sleeve must be fashioned as a relatively thick-wall plastic piece, which is very bulky. A plastic piece must be much thicker than a metal outer sleeve in order to transmit a corresponding amount of force. The seal produced in this already described plug-in coupling for connecting a hose to a pipe between the inner and the outer sleeve in the region of an inwardly directed radial ridge of the outer sleeve has the danger that the medium being transported will get into the nonsealed edge of the hose and thus impregnate the fabric or weave of the hose, with the known disadvantageous consequences.
Furthermore, another typical plug-in coupling is described in French Patent No. FR 26 67 922 A1, in which the plug-in coupling basically consists of an inner sleeve connected to an outer sleeve and a pipe socket. The pipe socket has a spring lock element, connected to the outer piece by a sealing ring arranged in a groove of the outer piece. In this plug-in coupling there is the disadvantage that the outwardly opening radical groove to accommodate the sealing ring is molded solely from the inner sleeve, which involves large manufacturing expense. Such a single-piece groove can only be crimped in a metal sleeve by a relatively complicated crimping process, which produces additional costs in the manufacture of such typical plug-in couplings. The making of a groove by a crimping process in plug-in couplings according to FR 26 67 922 A1 has the further disadvantage that the radii on the edge of the groove, i.e., where the vertical walls rise up, are configured relatively large and, thus, there is the danger that a sealing ring under pressure will be forced into these large spaces and then can no longer fulfill its sealing function against the opposite piece. Another substantial disadvantage of this plug-in coupling is that a relatively large axial length exists between the connection of inner and outer sleeves and the sealing ring, so that the room for inserting the hose in the connection space between inner and outer sleeve is relatively short (short axial length) and, therefore, the hose is supported and held only for a relatively short axial length. In order to assure a sufficient axial support length for the purpose of application of the hose in the plug-in coupling according to FR 26 67 922 A1, this coupling must be correspondingly material-intensive for its axial length and, thus, unattractive in price.